I was teaching all non-CS majors, and it was a summer course. Most of my students either had jobs or were taking other classes. I have no data to back it up, bu

I was teaching all non-CS majors, and it was a summer course. Most of my students either had jobs or were taking other classes. I have no data to back it up, but my intuition is that if the exam had not been graded, they would have, rationally, not put their full effort into it.